Electrical control circuit for electromechanical door operator



April 26, 1966 F. J. KALOQ ELECTRICAL CONTROL CIRCUIT FOR ELECTROMECHANICAL DOOR OPERATOR 4 Sheets-Sheet 1 Filed Dec. 10, 1963 INVENTOR FRANCIS J. KALOG ATTORNEYS FIG. 3

April 26, 1966 F. J. KALOG 3,247,615

ELECTRICAL CONTROL CIRCUIT FOR ELECTROMECHANICAL DOOR OPERATOR Filed Dec. 10, 1963 4' Sheets-Sheet 5 122 MOTOR CONTROL CIRCUIT I24 SIGNAL &SAFETY CIRCUIT l 22 MOTOR POWER CIRCUIT INVENTOR FRANCIS J. I XALOG BYM WW M ATTORNEYS a? F. J. KALOG April 26, 1966 ELECTRICAL CONTROL CIRCUIT FOR ELECTROMECHANICAL DOOR OPERATOR 4 Sheets-Sheet 4 Filed Dec. 10, 1963 1.5016 NEEOQ EOPOS:

QIN

INVENTOR.

PW m Ea uio zou @995 @5016 KPZm w 2o@ EaumU mm oa moko ATTORNEYS United States Patent 3,247,615 ELECTRICAL CONTROL CIRCUIT FOR ELECTRO- MECHANICAL DOOR OPERATUR Francis J. Kalog, New Britain, Conm, assignor to The Stanley Works, New Britain, Conn., a corporation of Connecticut Filed Dec. 10, 1963, Ser. No. 329,492 11 Claims. (Cl. 4930) The present invention relates to electromechanical actuators of the type commonly used for effecting the timely opening and closing movement of pedestrian exit or entrance doors.

It is an object of this invention to provide an improved electromechanical actuator having a control system including an electrical time delay circuit for controlling the braking of the drive motor during the closing movement of the door and an independent time delay circuit for initiating the reversal of the drive motor if a pedestrian approaches the entrance of the door during the door closing movement. Included in this object is the provision of an arrangement whereby the relative time delays of the two time delay circuits may be varied to accommodate door installations involving different inertia conditions.

It is another object of this invention to provide an improved arrangement for simultaneously opening and closing two doors having independent electromechanical actuators. Includedwithin this object is the provision of means for electrically interlocking the two independent electromechanical actuators so that each door is controlled by a signal initiated by the control system of either actuator.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the invention which will be indicated in the appended claims.

In the drawings: I

FIG. 1 is a perspective view, partly broken away, of a door installation incorporating the electromechanical operator of this invention;

FIG. 2 is a schematic view of a mechanical transmission subassembly of the electromechanical operator of FIG. 1;

FIG. 3 is a schematic diagram of an electrical control system of the electromechanical operator of FIG. 1;

FIG. 4 is a schematic perspective view of a door installation incorporating a pair of swinging doors each having an electromechanical operator which is mechanically independent of the electromechanical operator of the other door; and

FIG. 5 is a schematic diagram of an electrical control system for the mechanically independent electro-mechanical operators of FIG. 4.

Referring to FIG. 1, the electromechanical actuator embodying this invention is shown as being mounted in a header above a doorway for opening and closing a door 10. As shown in FIG. 1, the mechanical actuating components of the door operator are mounted on a base plate 14 so that they may be installed and removed as a unit, generally designated by numeral 15, and includes a reversible motor 16, which is shown as being of the alternating current capacitor type, and has its output shaft drivingly connected to reduction gearing 18 through a coupling 19. There is further provided a final drive assembly 20 driven by the reduction gearing 18 and having a downwardly depending output spindle 22 positioned in axial alignment with the pivot axis of the door 10. Spindle 22 is drivingly connected to door'lll through a coupling recess 24 for opening and closing door 10. A cooling flan 28 driven by fan motor 30 is provided to cool motor Also shown as being mounted on base plate 14 is an electrical control unit 32 which houses a major portion of the components of the electrical system for controlling the operation of the motor.

In order to provide a pedestrian-responsive signal for energizing the motor 16 to operate the door 10, a conventional switch-type contact carpet 34 is provided. It is apparent that such a signal could also be. provided by a conventional photoelectric sensing system or by hardware mounted for manual actuation by pedestrians using the doorway. As shown, the contact carpet 34 comprises two portionsan approach or entering carpet 36 which 7 is adapted when walked upon to close an approach switch 38 (FIG. 3), and a hold or safety carpet 40 over which the door is operated and which is adapted to close the.

Referring specifically to FIG. 2, the reduction gearing 18 has an input shaft 44 which is driven by motor 16 through the coupling 19 (FIG. 1) and, in turn, drives an output crank 46 in a clockwise direction, as seen in FIG. 2, when the motor 16 is driven in the forward, or dooropening direction. The reduction gearing 18, which may be of any suitable type, drivingly connects the input shaft 44 to the output crank 46.

The final drive unit 20 includes a rotatable clutch 52 connected to rotate door spindle 22. A drive link 58, having its ends pivotally mounted on both crank 46 and pivot 23 of clutch 52 rotates clutch 52 when crank 46 is rotated in a clockwise direction.

The final drive unit 20 is more fully described in copending application Serial No. 215,710 assigned .to the same assignee as this invention.

FIG. 3 illustrates an electrical control system for controlling the electromechanical actuator. The electrical system includes a master switch 120 for connecting the system to an electrical power source which, in the specific embodiment shown, is a conventional alternating current -120 volt source. Generally, the electrical control system includes three circuits: a motor power circuit designated 122 connected directly to the AC. source through the master switch a signal and safety circuit designated 124 connected to the AC. source through the master switch 120 and a step-down transformer 126 preferably having 24 volts output; and a motor control circuit designated 128 connected to the secondary or output of the transformer 126 through a rectifier bridge 130 preferably having 24-volt DC. power output.

In FIG. 3, the switches and relay contacts are illustrated as "being either open or closed to correspond with their condition when the master switch 120 is closed and neither approach switch 38 nor safety switch 42 is actuated.

Four normally closed door-cycle switches 132, 134, 136 and 138 in the motor control circuit 128 are mounted for selective operation by a pair of cams and 142 fixed to the output crank 46 for rotation therewith (see FIG. 2). The switches 132 and 134 are supported by a plate that is adjustably mounted for angular movement about the axis of rotation of the outputcrank 46 and is held in adjusted position by the screws 152. The switches 136 and 138 are similarly supported upon a plate 154 that is adjustably mounted and held in adjusted position by the screws 156. The plates 150 and 154 and,'therefore, the position of the normally closed door-cycle switches 132, 134, 136 and 138 relative to the cams 140 and 142 is selected so that the door closing limit switch 134 is open when the door is closed, but closes just after a the door begins to open and remains closed until the door returns to its fully closed position; the switch 136 is door opening limit switch which is closed except when the door is in its fully open position; the door opening damping switch 138 is open when the door is closed and is closed when the door is open approximately 75 or more; and the door closing damping switch 132 is open when the door is closed and is momentarily closed as the door passes through the approximately 25 open position.

Upon closing the master switch 120, the fan motor 30 is energized for continuously driving the fan 28, and power is applied to the terminals of the carpet-operated approach switch 38 and safety switch 42 so that they are ready to energize cycle-initiating relay A and safety relay B, respectively. The door-opening relay C, the motor forward-control relay D, the motor reverse-control relay E and the motor low-speed relay F in the motor control circuit 128 remain de-energized while the door is fully closed and are selectively energized as hereinafter more fully described for controlling the opening and closing of the door.

The normal opening and closing cycle of the door is initiated upon the closing of the approach switch 38 by a pedestrain walking on the entering carpet 36. Approach switch 38 then energizes the cycle-initiating relay A which closes the contacts A-1 to complete the circuit to the dooropening relay C and to the time delay circuit comprising the capacitor 160 and the resistor 162 which minimizes surges of current through switching contacts A4. The door-opening relay C, in turn, closes the contacts C-Z to enegrize the motor forward control relay D and opens the contacts C4 to prevent the motor reverse control relay E from being energized when the door closing limit switch 134 closes as the door is moved from its fully closed position. Further, the door-opening relay C closes the contacts C1 in the signal and safety circuit and opens the contacts C3 to prevent the energization of the safety relay B thereby assuring that the subsequent closing of the safety or holding switch 42 by a pedestrain as he steps from the entrance carpet to the exit or safety carpet 40 will continue to energize cycle-initiating relay A and will notenergize the safety relay B to terminate the opening movement of the door.

As a result of the energization of forward-control relay D, the contacts D-1 of the motor power circuit 122 are also closed to apply full line voltage to the motor fields 33 and 33a to turn the motor in the forward direction for opening the door. The energization of forwardcontrol relay D also closes the contacts D2 of the motor power circuit 122 to connect the resistor 164 and contacts F-l which are subsequently closed to obtain reduced speed operation of the motor. Further, energization of the forward-control relay D opens the contacts D-4 of the motor control circuit 128 to disconnect the time delay circuit for the low-speed relay F comprising the capacitor 166 and resistor 168 and also closes the contacts D-3 to connect the low-speed relay F to the switch 138.

Immediately after the motor 16 rotates to turn crank 46 clockwise (FIG. 2), the normally closed door closing limit switch 134 closes as it is disengaged by cam 140 so that the reverse-control relay E will be energized by the subsequent closing of contacts C-4.

After the door has opened about 75, the normally closed door opening damping switch 138 is closed as it is disengaged by the cam 142 fixed to the output crank 46 to complete the circuit to the low-speed relay F. Low-speed relay F, in turn, closes the contacts F1 in the motor power circuit 122 to place the resistor 164 in 'parallel with motor field 33a through the contacts D-Z which were previously closed by the motor forwardcontrol relay D, thereby to effect a reduced torque output from the motor 16 and slow or dampen the opening 4 movement of the door. Contacts F-2 of the damping circuit for capacitor 166 are also opened so that the discharge circuit provided therethrough for capacitor 166 is not effective.

When the door reaches the or full open position, the normally closed door open limit switch 136 is opened by the cam 14% fixed to the output crank 46 to open the circuit to the forward-control relay D, thereby returning the contacts D-1, D-Z, D-3, and D-4 to the positions shown in FIG. 3. This removes the electrical power from the motor field windings 33 and 33a to terminate the opening movement of the door. The circuit to the low speed relay F is also opened by the opening of contacts 13-?) and the time delay circuit comprising the capacitor 166 and resistor 163 is connected across low speed relay F by the closing of contacts D4. As the capacitor 166 of the time delay circuit for the low speed relay F was not previously energized since contacts D-4 were open, it does not cause a delay in the de-energization of low speed relay F. Accordingly, contacts F1 in the motor power circuit immediately open and the contacts F-2 of the discharge circuit for capacitor 166 are immediately closed through the resistor 169 to prepare the same for subsequent operation.

The door remains open as long as either the approach switch 38 or safety or hold switch 42 remain closed to energize cycle-initiating relay A and door-opening relay C and, therefore, as long as a pedestrian is standing on the contact carpet 34. However, when both the safety and approach switches 42 and 3% become opened simultaneously, the, cycle-initiating relay A is de-energized, thereby opening the contacts A-l to break the circuit to the door-opening relay C. However, after contacts A-1 open, the door opening relay C remains energized for a short interval of time due to the time delay circuit comprising the capacitor 160 and resistor 162 which discharges through door-opening relay C to maintain the contacts C-4 of the motor control circuit 128 open so that the door will dwell at the full open position.

As the capacitor 1160 becomes discharged, the dooropening relay C is de-energized, the contacts 04 are closed to complete the circuit to the motor reverse control relay E which, in turn, closes the contacts E-l to apply full line voltage to the motor fields 33 and 33a in the reverse direction for reverse rotation and closes contacts 13-2 to connect resistor 164 and contacts F1 for subsequent use in the reduced speed operation of the motor. Also the contacts C2 are opened when the relay C is tie-energized. The door then moves toward its closed position with initial closing movement of the door being accompanied by the immediate closing of the door opening limit switch 136 by cam 140 so as to prepare the forward relay D for energization by the reclosing of contacts C-2.

The door opening damping switch 138 is opened by cam 142 after 15 of closing travel of the door. The door closing damping switch 132 is then momentarily closed when the door rotates through 65 of its closing travel then to momentarily complete the circuit to the lowspeed relay F through the contacts D-4 and to energize its time delay circuit comprising the capacitor 166 and resistor 168. The energization of the relay F closes the contact F-l in the motor power circuit 122 to place resistor 164 in parallel with the motor field 33 to thereby reduce the torque of the door as it approaches its closed position. The time delay circuit for the relay F insures that relay F will continue to be energized for the normal closing period of the door and until the door reaches the fully closed position whereupon the door closing limit switch 134 is opened to de-energized the motor reverse control relay E and thereby open the contacts E 1 and E-Z and disconnect the power from the motor. As soon as the motor low speed-relay F is de-energized upon dissipation of the charge on the capacitor 166, the contacts F2 will close to completely discharge capacitor 166,

through the resistor 169 and the door closing cycle is I completed.

If the normal delay period provided by the time delay circuit for the relay F terminates prior to the door reaching its fully closed position as, for example, due to a retardation of the door by wind, the low speed relay P will be de-energized to open the contacts F-l so that full voltage is applied to motor fields 33 and 33a and full torque will be applied to close the door.

In the event that a pedestrian steps on the safety or holding carpet 40 to close the switch 42 as the door is closing, the circuit to the safety relay B is completed thereby opening the switch B-l to prevent energizing the cycleinitiating relay A. Consequently, if the door is in its closing cycle, it will continue to close. If however, a pedestrian steps onto the safety carpet 40 during the opening movement of the door, the safety switch 42 will continue to energize cycle initiating relay A since door opening relay C is energized and opening movement of the door will continue.

If at any other time during the closing movement of the door the approach switch 38 is closed as, for example, by a pedestrian stepping onto the approach carpet 36, the cycle initiating relay A will be energized to close the circuit to the door opening relay C thereby opening the circuit to the reverse control relay E by opening contacts C-4. However, since the door may be closing at rapid speed and, therefore, possess a substantial amount of kinetic energy, there is provided in accordance with one aspect of this invention, an arrangement whereby there is a delay in the energization of the door opening relay C when the approach switch 38 is closed when the door is in its door closing cycle.

Referring again to FIG. 3, the closing of approach switch 38 will, during the closing movement of the door, energize the cycle initiating relay A of the signal and safety circuit. The closing of the cycle initiating relay causes contacts A-1 and A4 to close. Since motor reversing relay E continues to be energized, contacts E-3 in series with door opening relay C, are open so that the door opening relay C may be energized through resistor 163. Also, under these conditions motor low speed relay F is energized through contacts A-1, E4 and A-2, all of which are closed. The energization of motor low speed relay F causes switch F-l of the motor'power circuit to be closed to reduce the speed of movement of the door and to absorb its kinetic energy.

While the energization of motor low speed relay F is substantially simultaneous with the closing of approach switch 38 and the energization of cycle initiating relay A, (normally closed contacts F-2 serving to prevent time delay capacitor 166 from having a significant eifect on the buildup of current through relay F), the effective energization of door opening relay C is delayed due to the resistance placed in series therewith (contacts E-3 being open) and the capacitor circuit paralleling the door 7 opening relay C provided by capacitor 160 and resistor 162. While the amount of time delay provided for absorbing the kinetic energy of the door may be increased by increasing the resistance value of resistor 163, we have found that in most installations a time delay of about 0.2 to 0.27 second is adequate to reduce the mechanical shock of reversing the direction of movement of the door to within acceptable limits.

If approach switch 38 is opened during the time delay interval before door opening relay C is effectively energized, cycle initiating relay A is de-energized to open contacts A-l thereby to discontinue the energization of door opening relay C and motor low speed relay F. Therefore, the motor reversing relay E, which continues to be energized, immediately reassumes control of the motor power circuit to complete the closing movement of the door in the usual manner. Thus, the time delay circuit for door opening relay C as provided by resistors door installation and are not shown in FIG. 5, it is repeated reversing shocks on the electromechanical operator as would otherwise occur if, say, a child were rapidly stepping on and off the approach contact carpet 36.

However, if approach switch 38 is closed for an interval which is longer than the time delay required before door opening relay C is effectively energized, and continues to be closed thereafter, contacts C-2 of the motor control circuit will be closed to energize motor forward control relay D to open the door in the usual manner as hereinbefore discussed.

Referring now to FIGS. 4 and 5, there is shown an embodiment of the invention wherein each of the doors of a swinging double door assemblyis provided with an electromechanical actuator, entrance and exit carpets, and control system. In this embodiment, however, the control systems are electrically interconnected, as'hereinafter described, so that the doors under all conditions of operation will be responsive to the signal received from either entrance or exit mat and will operate substantially in unison even though there are no mechanical connections between their respective electromechanical actuators.

The reference symbols used in FIGS. 4 and 5 utilize numerals corresponding to those of the embodiment of FIGS. 1 to 3 to indicate a like part but have the sufiix a added to indicate a like part of one of the actuators for one of the doors and the sufiix b added to indicate a like part of the actuatorfor the other door.

Moreover, while certain of the control elements in actuator I of FIG. 3 are not utilized in a swinging double contemplated within the scope of this invention that, as

' a matter of manufacturing and stocking convenience, all

ping on either of the entering carpets 3611 or 36b. This energizes the cycle initiating relay Ab of control circuit for actuator II which, in turn, closes contacts A-1b to energize door opening relay Ca by completing a circuit through closed contacts E-3b, lead 180, door opening relay Ca, rectifier a, lead 181,'door opening relay Cb and rectifier 13011.

With door opening relay Ca energized, the switches associated therewith are activated so that they assume an open or closed relationship opposite that shown in FIG. 5. Thus, contacts C-Za close to energize motor forward control relay Da to apply voltage across the motor of actuator I so that the associated door is driven in the door opening direction.

Cycle initiating relay Ca closes contacts C-1 a of signal and safety circuit of actuator I. This places the motor forward control relay Db of actuator II across rectifier 13012 by closing the circuit from the rectifier 13012 through lead 182, contacts C1a, lead 183, door opening limit switch 136, relay Db, back to the rectifier 13Gb. With the relays Da and Db energized, the contacts D-1a and Dll=b of the motor power circuits of the actuators are closed to energize both motors. In this regard, the connections of motor terminals of actuator II to the power .leads containing the contactors D-llb and E-lb have been reversed to schematically provide for the opposite 1 rotation of the motors so that the two doors open in the same direction.

As the doors have been opened about 75, the normally closed door opening damping switches 138a and 13% are closed as they are disengaged by the cams 142 fixed to the output crank as hereinbefore described in connection with the embodiment FIGS. 1-3. The closing of switches 138a and 13811 completes the circuit to motor low speed relays Fa and Pb which, in turn, closes contacts F-la and F-lb in the motor power circuits to effect reduced torque output from the motors 16a and 16b to slow the opening movement of the door. I

When the doors reach the 90 or full open position, the normally closed door opening limit switches 136a anl 13Gb are opened by the cams 140 to open the circuits to motor forward control relays Da and Db thereby returning the contacts D-la, D2a, D3a, and D- ia and D1b, D-2b, D-3b, and D4-b to the positions shown in FIG. 5. This completely removes electrical power from the motor field windings of the motors of actuators I and II to terminate the opening movement of the doors. It also opens the circuits to motor low speed relays Pa and Pb to immediately de-energize the same since capacitors 166a and 16% were not previously energized due to the fact that contacts D-4a and D4b were open. Accordingly, contacts F-1a and F-llb of the motor power circuits 122a and 1122b are immediately opened by the opening of the door opening limit switches 136a and 136b.

The doors remain opened as long as either the approach switches 38a or 38b or the safety or hold switches 42a or 42b remain closed to continue the energization of cycle initiating relay Ab as hereinbefore described. However when approach and safety switches 38a, 38b and 42a and 42b become open simultaneously, the! cycle initiating relay Ab is de-energized thereby opening the contacts A-1b to de-energize relays Ca and Cb. Thus, contacts C4a of actuator I reassume their normally closed position and motor reverse control relay Ea is energized. Contacts C-3a of the signal and safety circuit of actuator I also assume their normally closed position and motor reverse control relay Eb is energized by being placed across rectifier 13Gb through lead 182, contacts C-3a, lead 184 and door closing limit switch 134b, which is closed except when the door is in its fully closed position. With relays Ea and Eb energized, the motors of the motor power circuits of the two motors are energized to apply full torque to drive the doors to a closed position.

As the doors continue to close, the door closing damping sw-itches 132a and 132b are momentarily closed as the door passes the position corresponding to 65 of the closing travel of the doors to momentarily complete the circuits of the motor low speed relays Pa and Pb through contacts D4a and D-4b. This also places a charge on the capacitors 166a and Mob which continue to energize the low speed relays Fa and Pb for a predetermined period of time so that the door approaches its closed position at reduced speeds as hereinbefore descnibed. The doors then assume their closed position as door closing limit switches 134a and 134b are opened at the fully closed positions of the door.

If either approach switch 38a or approach switch 33b is closed as the door is moving toward a closed position, cycle initiating relay Ab is re-energiz/ed. The energizing of relay Ab causes contacts A-lb and A-2b to be closed to energize motor low speed relay Pb since contacts E-4b are closed due to the energization of relay Eb. In this regard, it will be noted that relay Ba is placed in parallel with relay Ab by leads 185 and 186 so that contacts A-la are closed to energize motor low speed relay Fa since contacts E-4a are closed. As a result, contacts F1a and F422 of the motor power circuits are closed to cause the motors of the two actuators to slow down as hereinbefore described. It is desirable that both of the swinging doors begin to reopen simultaneously to permit the pedestrian to pass therethrough. In order to assure this operation, there is provided an electrical interlock between actuators I and II. Referring again to FIG. 5, it will be observed that contacts E-3b will be opened since the motor reversing relay Eb is energized during the door closing movement. Thus, door opening relays Ca and Cb are energized through resistor 163 which is placed in parallel circuit relation with contacts E3b. As hereinbefore explained, relays Ca and Cb are placed in series across rectifiers a and 13% through contacts A-lb which are connected to the positive terminal of the rectifier 130b, resistor 163 (when E3b is opened), lead 180, relay Ca, which is connected to the negative terminal of rectifier 130a, lead 18L and relay Cb which is in turn connected to the negative terminal of rectifier 13Gb. Thus, relays Ca and Cb are connected in series with each other and with resistor 163.

Connected in parallel with relay Co is a time delay circuit comprising capacitor a and resistor 162a and connected in parallel with relay Cb is a time delay circuit comprising capacitor llfitlb and resistor 1452b. Since the time required to charge capacitors 160a and lfitlb can be adjusted to produce the identical time delays in the eifective energization of relays Ca and Cb, it is apparent that the total time delay which is provided for absorbing the kinetic energy of the doors during reversal thereof can be set at any desired amount by adjusting the resistance value of resistor 163 irrespective of any other mechanical or electrical variations in the two independent actuators for the doors.

As previously explained, the energization of door opening relays Ca and Cb opens contacts C ia and C-3a to de energize motor reverse control relays Ea and Eb and to energize motor forward control relays Da and Db to cause the door to reopen in the normal manner regardless of the angular position of the doors between the full open and full closed positions. In this connection, if approach switches 38a and 38b and holding switches 42a and 42b are opened simultaneously, the door initiating relay Ab will immediately de-energize to open contacts 0-441 and C3a to de-energize door opening relays Ca and Cb so that contacts C-4a and C-3a close to cause the doors to move toward the closed position without reaching a full open position of the doors.

It can be seen, therefore, that the electromechanical actuators of this invention not only assure that the doors are quickly and positively opened and closed in response to pedestrian traffic without complete recycling regardless of the position of the door when the pedestrian signal is received, but additionally reduces the likelihood that the system will be subjected to severe inertial shocks in the event that a pedestrian steps on the entrance mat during the closing movement of the doors. Moreover, it provides a positive and adjustable time delay for preselecting the time provided for absorbing kinetic energy and assuring that, in the case of swinging double doors, both of the doors will begin to reopen simultaneously in response to pedestrian trafiic during the door closing movement thereof regardless of electrical or mechanical variations in the two actuators.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

1. In combination, an electromechanical door operator comprising a reversible electric motor and an electric control circuit for controlling the automatic operation of the motor during a door opening and closing cycle, said control circuit comprising a first switch operable to connect the motor to the power source to energize the sameto move the door in the door opening direction, a second switch effective to energize the motor in the door closing direction, a third switch responsive to the movement of the door to a preselected position during its closing movement to energize a relay to change the connection between the motor and the power source to modify the torque of the motor and to activate a first electric time delay circuit means for controlling the period of time the motor torque is modified, and electric circuit means responsive to the operation of said first switch during the closing movement of the door to energize said relay for modifying the torque of the motor and for activating a 9 second .time delay means which is independent of said first time delay means to render the first switch ineffective to energize the motor in a door opening direction for a predetermined period of time.

2. In combination, an electromechanical door opera ator comprising a reversible electric motor and a pedestrian-responsive electric control circuit therefor, said control circuit comprising a first switch connected to energize a first relay for connecting said motor to a power supply to drive the motor in a door opening direction, a second switch automatically operable when the door reaches a full opening position to reverse the motor to drive the motor in a door closing direction, a third switch responsive to the movement of the door to a preselected position during its closing movement to energize a second relay to change the connection between the electric motor and the power supply so as to reduce the speed of the motor and to activate a first electric time delay circuit means for continuing the reduced speed operation of the motor for the normal concluding portion of door closing movement, and electric circuit means responsive to the operation of said first switch during the closing movement of the door to energize said second relay to change the connection between the motor and the-power supply so as to reduce the speed of the motor and to activate a second electric time delay means which is independent of the first time delay means to render the first switch ineffective to energize the motor to dl'llVC the door in a door opening direction for a predetermined period oftime.

3. In combination, an electromechanical door operator comprising a reversible motor and a pedestrian-responsive control therefor, said control comprising a first switching means for connecting the motor t a power supply to drive the same in forward direction, a second switching means effective to energize the motor in a reverse direction, a third switching means connected to energize a relay to change the connection between the motor and the power supply to modify the torque output of the motor for a predetermined interval during the normal reverse movement thereof and to activate a first time delay means for controlling the duration of said predetermined interval, and control means responsive to the operation of said first switching means during the reverse movement of the motor and connected to energize a relay to change the connection between the motor and the power supply for modifying the torque of the motor and for activating a second time delay means which is independent of said first time delay means to render the first switching means ineffective to power the motor in a forward direction for a preselected interval of time.

4. In combination, an electromechanical door operator comprising a reversible electric motor and a pedestrianresponsive control circuit therefor, said control circuit comprising a first switch for connecting the motor across a power supply to energize the motor in the door opening direction, a door opening limit switch effective to energize the motor in the door closing direction, a third switch which momentarily closes as the door passes a predetermined position during its closing movement to energize a relay to change the connection between the motor and the power supply to reduce the torque of the motor and to activate a first electric time delay circuit means for continuing the reduced torque of the motor for a predetermined period of time corresponding to the period of time required to complete the normal closing operation of the door, and electric circuit means including a second electric time delay means which is independent of the first time delay means operable in response tothe operation of said first switch during the closing movement of the door to energize said relay for modifying the torque of the motor and to render the first switch ineffective to energize the motor in a door opening direction for a period of time determined by said second electric time delay means.

5. An electromechanical door operator comprising a reversible electric motor and an electric control circuit therefor, said control circuit comprising a first switch operable by pedestrian traffic passing through the door to energize a first relay to connect the motor to a power supply to drive the motor in the door opening direction, a door opening limit switch to de-energize said first relay and to energize a second relay to connect the motor to the power supply for driving the motor in a door closing position after the pedestrian traffic has passed through the door, a third switch momentarily operable as the door passes through a predetermined position during its closing movement to energize a third relay to change the connection between the motor and the power supply to reduce the speed of the motor and to charge an electric time delay circuit means for controlling the period of time the motor speed is reduced, and electric circuit means responsive to the operation of said first switch during the closing movement of the door to energize said third relay for reducing the motor speed and for charging a second electric time delay means which is independent of said first time delay means to determine the period of time during which the closing movement of the door continues and thereafter to render the first switch effective to energize said first relay to connect the motor to the power supply to drive the door in a door opening direction.

6. An electromechanical door operator comprising a reversible electric motor and an electric control circuit therefor, said control circuit comprising a normally open first switch adapted to be closed by pedestrian traffic passing through the door to energize a first relay to connect the motor to a power supply to drive the motor in the door opening direction, a door opening limit switch to de-energize said first relay to energize a second relay to connect the motor to the power supply for driving the motor in a door closing position after the pedestrian trafiic has passed through the door, a third switch momentarily operable as the door passes through a predetermined position during its closing movement to energize a third relay to change the connection between the motor and the power supply to reduce motor speed and to charge a first electric time delay circuit means for controlling the period of time the motor speed is reduced, and electric circuit means responsive to the operation of said first switch during the closing movement of the door to energize said third relay to change the connection between the motor and the power supply to drive the motor at a reduced speed so as to absorb the kinetic energy of the door and to charge a second electric time delay means for controlling the period of time the motor is driven at reduced speed in the door closing direction and to render the first switch effective to energize the motor in the door opening direction if said first switch continues to be closed after such period of time.

7. In combination, a pair of doors each having an electromechanical operator including a reversible electric motor and an electric control circuit therfor for driving the door to its opened and closed positions in response to a first switch actuated by pedestnian traffic therethrough, means interconnecting the control circuit of one operator with the control circuit of the other to connect the electric motor of each operator to a power source upon actuation of said first switch for opening and closing the doors simultaneously, the control circuit of each of the operators having a cam-operated switch operated at a preselected position of the closing movement of the associated door to energize a relay to change the connection between the motor thereof and the power source to modify the torque of the associated motor and to activate first electric time delay circuit means for controlling the period of time the motor torque is modified, and electric circuit means responsive to the operation of the first switch during the closing movement of the doors to energize said relay for causing the motor of each of the operators to operate at reduced speed and for activating second electric time delay circuit means which is independent of said first time delay means to render the first switch ineffective to enerl l gize the motors in the door opening direction for a predetermined period of time and thereafter to render the first switch eifective to energize both motors to drive the doors in the door opening direction simultaneously.

8. In combination, a pair of doors each having an electromechanical operator including a reversible electric motor and an electric control circuit therefor for driving the door in a door opening and closing cycle in response to the closing of a first switch actuated by pedestrian traffic, means interconnecting the control circuit of one operator with the control circuit of the other to connect the electric motor of each operator to a power source upon closing of said first switch for opening and closing the doors simultaneously, the control circuit of each of the operators having a switch momentarily closed at a preselected position of the associated door during its closing movement to energize a relay thereof to change the connection between the motor thereof and the power source to reduce the speed of the associated motor and to charge first electric time delay circuit means for contin-uing the reduced speed operation of the motor for the normal concluding portion of the door closing movement, and electric circuit means responsive to the closing of the first switch during the closing movement of the doors to energize said relay for causing the motor of each of the operators to operate at reduced speed and [for actuating second electric time delay circuit means to render the first switch ineffective to energize the motors in the door opening direction for a predetermined period of time and thereafter to render the first switch elTective to simultaneously energize both motors to drive the doors in the door opening direction.

9. In combination, a pair of doors each having an electromechanical operator including a reversible electric motor and an electric control circuit therefor for driving the door in a door opening and closing cycle in response to the closing of a first switch actuated by pedestrian traffic, means interconnecting the control circuit of one operator with the control circuit of the other to connect the electric motor of each operator to a power source upon the closing of the first switch :for opening and closing the doors simultaneously, the control circuit of each of the operators having a switch momentarily closed at a preselected position of the associated door during its closing movement to energize a relay thereof to change the connection between the motor thereof and the power source to reduce the speed of the associated motor and to change first electric time delay circuit means for continuing the reduced speed operation of the motor for the normal concluding portion of the door closing movement, electric circuit means responsive to the closing of the first switch during the closing movement of the doors to energize said relay for causing the motor of each of the operators to operate at reduced speed, the electric control circuit for each operator including an electric time delay circuit means which is independent of said first time delay circuit means with said last-mentioned electric time delay circuit means of the operators connected in series circuit relationship, said electric circuit means further being responsive to the closing of said first switch during the closing movement of the doors to energize said last-mentioned electric time delay circuit means to i2 render the first switch ineffective to energize the motors in the door opening direction for a predetermined period of time and thereafter to render the first switch efiective to simultaneously energize both motors to drive the doors in the door opening direction.

It In combination, a pair of doors each having an electromechanical operator including a reversible motor and an electric control circuit therefor for driving each door through an opening and closing cycle in response to a first switch actuated by pedestrian tratfic therethrough, means interconnecting the control circuit of one operator with the control circuit of the other to connect the electric motor of each operator to a power source to initiate the door opening and closing cycle for each of the doors simultaneously, each of said control circuits including an electric time delay circuit means interconnected in series with an electric time delay circuit means of the other circuit, and electric circuit means responsive to the operation of the first switch during the closing movement of the doors to energize a relay of each operator to change the connection of each motor and the power source for causing the motor of each operator to operate at reduced speed and for charging the serially connected electric time delay circuit means to render the first switch ineffective to energize the motor of each operator in the door opening direction for a predetermined period of time and thereafter to render the first switch eifective to simultaneously energize the motor of each operator to drive the doors in the door opening direction.

11. In combination, a pair of swinging doors each having an electromechanical operator including a reversible electric motor and a control circuit therefor, each operator further having a separate entrance mat containing a pedestrian-operated switch, means interconnecting the control circuit of one operator with the control circuit of the other to energize the electric motor of each operator for simultaneously initiating the door opening and closing cycle for each of the doors as a result of the actuation of the pedestrian-responsive switch of either of the entrance mats, electric circuit means for maintaining both of the doors in a full open position during the continuance of pedestrian traific therethrough and thereafter to initiate the simultaneous closing movement of both doors, the control circuit of each of the operators including an electric time delay circuit means interconnected in series with each other, and additional electric circuit means responsive to the actuation of the pedestrian-responsive switch of either of the entrance mats during the door closing movement for causing the motor of each operator to operate at reduced speed and for charging the serially connected electric time delay circuit means to cause the motor of each operator to operate at reduced speed for identical periods of time and thereafter to render the switch effective to simultaneously energize the motor of each operator to reopen the doors.

References (Iited by the Examiner UNITED STATES PATENTS HARRISON R. MOSELEY, Primary Examiner. 

1. IN COMBINATION, AN ELECTROMECHANICAL DOOR OPERATOR COMPRISING A REVERSIBLE ELECTRIC MOTOR AND AN ELECTRIC CONTROL CIRCUIT FOR CONTROLLING THE AUTOMATIC OPERATION OF THE MOTOR DURING A DOOR OPENING AND CLOSING CYCLE, SAID CONTROL CIRCUIT COMPRISING A FIRST SWTICH OPERABLE TO CONNECT THE MOTOR TO THE POWER SOURCE TO ENERGIZE THE SAME TO MOVE THE DOOR IN THE DOOR OPENING DIRECTION, A SECOND SWITCH EFFECTIVE TO ENERGIZE THE MOTOR IN THE DOOR CLOSING DIRECTION, A THIRD SWITCH RESPONSIVE TO THE MOVEMENT OF THE DOOR TO A PRESELECTED POSITION DURING THE CLOSING MOVEMENT TO ENERGIZE A RELAY TO CHANGE THE CONNECTION BETWEEN THE MOTOR AND THE POWER SOURCE TO MODIFY THE TORQUE OF THE MOTOR AND TO ACTIVATE A FIRST ELECTRIC TIME DELAY CIRCUIT MEANS FOR CONTROLLING THE PERIOD OF TIME THE MOTOR TORQUE IS MODIFIED, AND ELECTRIC CIRCUIT MEANS RESPONSIVE TO THE OPERATION OF SAID FIRST SWITCH DURING THE CLOSING MOVEMENT OF THE DOOR TO ENERGIZE SAID RELAY FOR MODIFYING THE TORQUE OF THE MOTOR AND FOR ACTIVATING A SECOND TIME DELAY MEANS WHICH IS INDEPENDENT OF SAID FIRST TIME DELAY MEANS TO RENDER THE FIRST SWITCH INEFFECTIVE TO ENERGIZE THE MOTOR IN A DOOR OPENING DIRECTION FOR A PREDETERMINED PERIOD OF TIME. 